The freshwater pearl mussel (Margaritifera margaritifera) is a critically endangered species found in a few rivers in the UK, primary in Scotland, Wales, and northern England. These long-lived bivavles play an important role in maintaining river ecosystems by filtering water and providing habitat for other species. However, they are under severe threat from habitat degradation, pollution, and declining host fish populations needed for their larval stage, which parasitises salmon and trout.
